The answer you're probably looking for is:
The Stamp Act of 1765 was significant in the sense that it was the first direct tax imposed on American colonists (So, 
would most likely be the answer that you're looking for to this question, that you have asked
Knights were indeed lower than vassals and held less prestige in medieval society. It's not true though, that knights didn't have enough prestige in medieval society. Vassals swore to the king or the ruler of a region, whereas knights often swore to vassals, so they still had people under them, but they were not at the top.
Alfred Thayer Mahan recommended that the American military should focus on sea-power as the key to its success in any contemporary or future conflicts.
C. NATO was America and our allies and the Warsaw Pact was the Soviets and their satellite states
